Study On Preparation Of Liquid Rubber By Twin-Screw Shearing And Its Modification

In the rubber mixing process,in order to improve some physical and mechanical properties of the rubber compound,such as reducing the Mooney viscosity and hardness of the system,low molecular oil compounds are usually added as plasticizers(commonly aromatic hydrocarbons)during rubber processing.substances).Liquid rubber is a new type of high-efficiency,green and energy-saving reactive plasticizer.The main preparation method of liquid rubber is anionic polymerization.This method has a high cost and limits its industrial application,while the degradation method has a lower cost,but its molecular weight and its distribution are not easy to control,so it is very important to study a new method that can reduce the cost and control its molecular weight conveniently.This subject adopts twin-screw as equipment and solid rubber as material,and prepares liquid rubber with different molecular weights by adjusting the temperature and rotation speed of the screw.The prepared liquid rubber was compared with aromatic oil and commercially available liquid rubber.In the second chapter of this thesis,using solid polyisoprene as raw material and using twin-screw equipment,isoprene liquid rubber with molecular weight from 9000-100000 was successfully prepared by thermooxidative degradation,and its structure was characterized.,the results show that LIR has been successfully prepared.The prepared LIR basically does not contain 1,2 structure and trans 1,4 structure.The number-average and weightaverage molecular weight of LIR both increase with the gradual increase of the twin-screw temperature and the gradual decrease of the rotational speed.And gradually decreased,but the molecular weight distribution did not change significantly.JLIR with different molecular weights was added as plasticizer to SBR and SSBR/BR matrix and characterized.The results show that adding medium molecular weight JLIR has better comprehensive performance.Comparing JLIR-320 with traditional aromatic oil and commercially available LIR-565,the plasticizing effect of JLIR-320 is studied.The results show that the plasticizing effect of JLIR-320 is much better than that of traditional aromatic oil.The plasticizing effect of LIR-565 is comparable.In the third chapter of this paper,using twin-screw as equipment,butadiene liquid rubber with molecular weight from 1000-9000 was successfully prepared by chemical degradation method,and it was characterized.The results showed that LBR was successfully prepared,and the number of LBR was The average and weight-average molecular weights both decreased gradually with the increase of the twin-screw temperature,while the molecular weight distribution first widened and then narrowed,and the rotational speed had no obvious effect on the size and distribution of the molecular weight.JLBRs with different molecular weights were added as plasticizers to SBR and SSBR/BR matrices and characterized.The results show that the comprehensive performance of medium molecular weight JLBR is better.Comparing JLBR-320 with traditional aromatic oil,commercially available LBR-305,and researching its plasticizing effect,the results show that the plasticizing effect of JLBR-320 is much better than traditional aromatic oil,and commercially available anionic polymerization The plasticizing effect of LBR-305 is comparable.